Air-compressing apparatus.



W. P. HAMMOND.

AIR COMPRESSI NG APPARATUS. APPLICATION FILED MAY 3, 1913.

1,1 4AM. Patented May 23, 1916.

PANT

WILLIAM P. HAMMOND, OF PASSAIC, NEW JERSEY, ASSIGNOR T0 GARRETT H. BROWN AND HENRY W. BROWN, OF SYRACUSE, NEW YORK, A COPARTNERSHIP UNDER THE FIRM-NAME THE BROWN COMPANY.

AIR-COMPRESSING APPARATUS.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed May 3, 1913. Serial No. 765,194.

To all whom it may concern:

Be it known that I, IVILLIAM P. HAM- MOND, a citizen of the United States, residing in Passaic, county of Passaic, and State of New Jersey, have invented certain new and useful Improvements in Air-Compressing Apparatus, of which the followingis a full, clear, and exact specification.

My invention relates to air compressing devices of that type commonly known as spark plug pumps, which are designed to be attached to one cylinder of a multiple cylinder engine by connection with the sparkplug aperture thereof and to be operated by the compression of said cylinder. Some spark-plug pumps of this type are not only operated by the compression of the engine, but also utilize the operating compression fluid from the engine by stepping the pressure thereof to a higher degree by and during the operation of the pump, then utilizing the same for the inflation of pneumatic tires. In such a structure the gas cylinder contents is passed to the tire and not being entirely free from deleterious substances, such as gasolene fumes, lubricating oil, and like substances, chemical deterioration of the rubber in pneumatic tires may take place. Under the action of these substances, rubber hardens, losing its elasticity and tenacity and develops a tendency to wear out quickly. The desirability of pumping pure fresh air unladen with such substances to the tires becomes at once apparent. It is the purpose of my present invention to eliminate the objectionable features of the pump suchas I have just described, and produce an apparatus which, while operating in the same general way, will obtain its supply of fluid to be compressed directly from the atmosphere, the same being drawn directly into a compressing chamber of the pump without previously having been admitted to the engine cylinder.

In the accompanying drawings I have illustrated one preferable embodiment of my invention showing same in sectional eleva tion.

In detail the pump is comprised of a compression cylinder 1, a compression cylinder 2 of smaller diameter with an intermediate cushioning cylinder 3. Mounted Within these cylinders and arranged to reciprocate therein are differential pistons 4, 5, and 6.

Pistons 4 and 6 being compression pistons, while the piston 5 serves as a cushioning piston cushioning the up stroke of the plural pistons. These pistons are joined and operate in tandem by means of a piston rod 7. Cylinders 1, 2 and 3 are separated from each other by partitions 8 and 9 having central apertures through which the piston rod 7 is caused to reciprocate. These apertures are provided with suitable stutling boxes 10 and 11 so as to form an air-tight connection between the reciprocating piston rod and the partitions. The lower cylinder 1 is provided with a screw threaded boss 1'2 adapting the pump to be readily attached to a spark-plug aperture of an internal combustion engine, a fragmentary portion of which is indicated at 13. The downward stroke of the pump pistons is cushioned by means of an upwardly projecting hollow cylindrical member 14, which is in screw threaded engagement with the bottom of the pump cylinder 1, this member is received in an opening 15 in the bottom of the lower piston 4. As soon as the down stroke of the piston 4 reaches the projection 14 air becomes trapped between the lower surface of the piston and the bottom of the cylinder 1, thus forming an air pocket and cushioning the blow of the pistons. Likewise on the up stroke of the pistons, as soon as the piston 5 passes apertures 16, air becomes trapped between the piston 5 and the partition 9, thus cushioning the up-stroke of the pistons.

I The piston rod 7 is provided with a passage way 17 controlled by a ball valve 18, held to its seat by a spring 19. Thispassage way mosphere by a valve controlled opening 23,

in which is positioned an inwardly opening valve 24. I may, if I so desire, employ a similar inwardly opening valve in the communication between the lower pump cylinder and the engine cylinder, such as I have illustrated and indicated at 25. This latter valve being used to augment or increase the engine compression where, in the event that the engine throttles are not separately manipulated to meet the requirements of the pump in order to have it operate under its greatest efiiciency.

The operation of the pump is thought to be apparent. Upon the compression stroke of the engine piston the piston 4 is forced upwardly carrying with it the pistons 5 and 6, and upon the suction stroke of the engine piston, these pistons are caused to descend. Upon the descending stroke of the pump pistons, atmospheric air is drawn into the compression chamber of the cylinder 1 through the valved port 23. Upon the succeeding upstroke of the pump pistons, this air is forced by compression through the passage 17, unseating valve 18, and entering the sub-chamber 20, filling the latter at a pressure in excess of atmospheric pressure by reason of its former compression in the lower pump cylinder. Upon the succeeding down-stroke of the pistons, this air trapped by reason of the ball valve 18 within the sub-chamber 20 automatically transfers itself by bleeding past the cup-shaped washer 6, which on this stroke assumes a condition of collapse, thereby charging the upper pump cylinder, with this pure atmospheric air at a still further increased pressure. Meanwhile the compression cylinder 1 has drawn in and become charged with air at atmospheric pressure. On the next succeeding upstroke of the piston the fully charged pump cylinder 2 is put under further compression by the piston 6, which increases the pressure of the air and forces it to the tire or other place of use through valve controlled outlet 26.

I do not wish to be limited to the precise details of construction as the same may be changed or varied without departing from the spirit and scope of my invention as set forth in the appended claims.

Having thus described my invention what I claim as new herein and desire to secure by Letters Patent, is:

1. In an impulse pump, the combination of a power cylinder, a cushioning cylinder and a compressing cylinder, connected pistonsin said cylinders, a valve-controlled inlet to the power cylinder above the piston therein, a passage affording free communication between the atmosphere and the cushioning chamber, and a valve-controlled passage leading from the power cylinder above the piston therein to the compressing cylinder below the piston therein, substantially as described.

2. In an impulse pump, the combination of a power cylinder and a compressing cylinder, said' compressing cylinder being of less diameter than the power cylinder, connected pistons working in said cylinders, a valve-controlled passage leading from the atmosphere to the power cylinder above the piston therein, a valve-controlled passage leading through the connectingmember connectingthe pistons from the power cylinder above the piston therein to the compressing cylinder below the piston therein, and a cushioning chamber intermediate the power and compressing cylinders.

In witness whereof I have hereunto set my hand in the presence of two subscribing witnesses.

WVILLIAM P. HAMMOND. Witnesses:

IRENE M. MULGAY, LILLIAN L. MALZER. 

